Recent Talks

Today we largely understand the large scale evolution of the Universe but we have only little knowledge of the small scale physics involved in forming and evolving the baryonic structure (gas, stars and dust) of galaxies. Dwarf galaxies are considerd to be the ideal ”galactic laboratories” to gain insight into the astrophysical processes governing galaxy evolution in general. The obvious main feature of a dwarf galaxy is, that it is small - about 1/10 of the Milky Way’s size. Their relatively shallow gravitational potential makes them very sensitive to the different (astro)physical processes that affect galaxy evolution and counteract gravity. Hence we can use these galaxies to try to understand and answer the questions we still have about how, when and why galaxies form stars, stop forming stars, and recycle stellar-synthesised elements in the interstellar medium. Experimenting in these “galactic laboratories” is of course confined to the virtual universe, which we do by running state- of-the-art Nbody-SPH simulations of dwarf galaxy formation and evolution. Due to their small dimensions, these can achieve much higher resolution and physical detail than any other type of galactic simulations. In this talk, I will discuss the main prop- erties/parameters determining the behaviour and appearance of the dwarf galaxy models, and use the results to compare with and explain observations.

The flow of gas from the cosmic web into galaxies provides the necessary fuel for star formation and galaxy assembly. I will review our current knowledge about gas accretion into galaxies and its consequences for galaxy formation at high and low redshifts. Special attention will be given to the detectability of cold streams as Lyman-alpha blobs or Lyman-Limit systems, as well as the current challenges to the cold-flow picture.

Se revisará el estado de los instrumentos instalados en los telescopios del Observatorio del Roque de Los Muchachos (ORM) y del Observatorio del Teide (OT). Se hará una breve introducción para hablar sobre las diferentes maneras de acceder a tiempo de telescopio (anuncios de oportunidad normales, noches de servicio y DDT). El objetivo de esta charla es ayudar a preparar propuestas de observación para el semestre 14A. Habrá tiempo para preguntas y comentarios.

In the last years star-forming regions and massive protostars have been suggested to be gamma-ray emitters. Isolated massive protostars present powerful outflows interacting with the surrounding medium. Some of these sources power non-thermal radio jets, indicative of particle acceleration up to relativistic energies. At the jet-termination region strong shocks form which can lead to gamma-ray emission, as theoretical models predict. It has also been prognosticated that the combined effect of several low-mass protostellar objects may produce significant amount of gamma rays. We present here two studies: IRAS 16547- 4247, an isolated protostar showing non-thermal radio emission; and Monoceros R2, a star forming region coincident with a source of the 2nd Fermi-LAT catalog. In the first case, we analized archival X-ray data and detected the source. We also studied the system in a broad- band one-zone model context and tried to fit the X-ray detection with a non-thermal model. In the second case, we analyzed 3.5 years of Fermi-LAT data and confirmed the source with a detection above 12 sigma. Our results are compatible with the source being the result the combined effect of multiple young stellar objects in Monoceros R2.

Dark matter makes up most of the mass of the Universe but remains mysterious. I discuss recent progress in constraining its properties by measuring its distribution in the Universe from tiny dwarf galaxies to giant galaxy clusters, and comparing this with numerical simulations. The latest results favour a cold, collisionless particle that must lie beyond the standard model of particle physics. I discuss the known small scale problems with this model: the cusp-core and missing satellites problems, and I argue that these are likely due to baryonic "feedback" during galaxy formation. I conclude with a discussion of experiments underway to detect dark matter particles, and the role that astrophysics has to play in these too. There is an exciting a very real prospect of detecting a dark matter particle in the next five years.

3- Other spectroscopic surveys and analysis strategies

- eBOSS, BigBOSS, HETDEX, WEAVE, 4MOST

- data mashup: astrometry,  photometry and spectroscopy together

- reconstructing the Galaxy

- 'observing' galaxy simulations

- discovery and follow-up of interesting/exotic targets: HVS, UMPS, CEMPS, RCrBs...

5- Some current problems and opportunities

- simulating kinematics

- simulating variables

- simulating non-solar scaled populations

- simulating rare and extreme populations (e.g. X-ray sources, PNe,

  hot-WDs, AGB-manque', C stars, IR-emission by mass-losing stars)

- opportunities opened by asteroseismology

5-   The Galactic halo

- mass, extent, shape

- substructure, inner/outer halo

5- The Galactic bulge

- observational status on bulge kinematics and chemical properties in the context of other bulges

- ideas about the formation of the bulge

5- SPH basics

- numerical viscosity

- Kelvin-Helmholtz instabilities

- other problems and their amelioration